Colored and tinted parchment paper and the like and process for the manufacture of the same



Patented Nov. 41, 19%) ROBERT IRVING COWEN, OF N EW YORK, N. Y.

COLORED AND TINTED PARCHMENT' PAPER AND THE LIKE AND PROCESS FOR THE MANUFACTURE OF'IQHE SAME No Drawing.

Hitherto the manufacturers of parchment papers have not been able to produce satisfactory and reliable results in making tinted and colored parchment. papers; they have 5. also been somewhat limited in the variety of colors which could be successfully applied to papers of this character; and, again, it has been found under present known methods that, in order to produce deeper shades of color with dyes, large excess of the amounts necessary to produce the desired coloring will have to beused in the processes, involving considerable loss in dyestufls.

As is generally known, parchment paper is made by passing unsized paper through a parchmentizing bath, for instance, sulphuric acid, and then through a clear water bath in order thoroughly to wash the paper free from excess of the acid. By this treatment a surface film of amyloid is formed upon both sides of the paper and around each fiber, the thickness of such film depending principally upon the time of immersion of such unsized paper in the acid bath, the temperature of the bath, the texture ofthe paper, etc. llhis amyloid film or coating produces so-called parchment paper or vegetable parchment. In the process heretofore employed for the production of colored papers of this character, the tint or color 'is incorporated in the beaters, or applied to the web by a print roll before or after going through the calenders as stated; by this process the resultis not always satisfactory, and the depth of shade and the number oficolors which can be specially utilized is limited.

If colored parchment paper is to be made by adding the dyestuff to the heaters. the manufacturer is limited'as to the dyestuffs he can use for the following reasons. Acid and direct dyes cannot be used without a mordant,

as they will not attach themselves to the fibers with any permanency and will mostly be washed out in the white water when the beaten stock is run on to the wire. If a mordant, such as rosin size or alum, or a combination of the two is used, the paper will not parchmentize properly or at all when it is run. through the parchmentizing bath. Thus acid and direct dyes cannot be used satisrib Serial No. 70,196.

dye left in the paper would be too small to cm color it satisfactorily. v

' I have found that papers of this class can be produced so as to enable the manufacturer to employ a wider range of colors and to do this more economically and more satisfactorily by my process than has been possible to do with the existing methods, and it is also possible to produce, for instance, a black parchment paper of highly satisfactory quality and which hitherto has not been made satm i isfaetorily. For instance, I am able, with my process, to produce yellow, orange, pink, blue, green, purple and black, or any other color, shade or tint of a high degree of perfection. r We By my process the dyestufis or coloring materials are so applied that they become incorporated in the amyloid film, which forms on the paper, or rather around the fibers of the paper, thus treated. Instead of applying ea the dyestufi's in the heaters for the purpose of coloring the pulp from which the paper is to be manufactured, I apply the coloring matter in the acid bath which is used for giving the-paper its amyloid coating. I have found thatthere are several types of coal-tar dyes especially which will do the work very satisfactorily in themanner indicated.

On adding an organic dye to concentrated 1 sulphuric acid, say of about seventy-five peragain, (5) the dye may not dissolve in the acid solution at all. I

The organic acid dyes, or most of them at least, are soluble in sulphuric acid, and, although some of these change in color or shade through the action of the acid or may give a colorless or nearly colorless parchmentizing bath, the original color reappears upon passing the treated paper through the water bath for washing out the excess of acid, and the paper is found to have been colored in a very satisfactory manner.

This class of acid dyes is mainly soluble in water, but, after the treatment in the manner indicated, the dye, being incorporated in the amyloid film itself, washes out very little in the subsequent treatment of the Water bath which is used to wash out the excess of acid. Obviously any dye which is chemically decomposed entirely by the acid is not serviceable. p

I have also found thatdyes which are insoluble in the acid bath may be used if they are present in fine suspension. For instance, when I use National Erie fast scarlet (color index No. 326) in such a suspension in the acid bath, the paper presents the same color as the plain parchment, but, when the paper is subsequently washed in a diluting bath, the dye begins to dissolveand colors the paper quite satisfactorily.

As an illustration of some of my experiences with various organic dyes of dilferent classes and the results to be obtained therewith, I may state at this point that chinoline yellow (color index No. 801) produces a yellow dye bath and produces a fine yellow color in the paper; auramine O concentrated (color index N o. 655) gives a colorless acid bath, but the color develops again on "washing and produces a good dyeing effect; orange A (color index No. 151) produces a red dye bath, but gives a good orange color to the paper after washing; croceine scarlet C (color index No. 252) produces a purple acid bath, but gives a good scarlet color in the finished paper; National Erie fast scarlet, which is insoluble in the acid solution and must therefore be suspended therein, produces a satisfactory color after passing through the wash bath; acid scarlet 3 R (color index No. 196) dissolves in the acid bath to a wine-red color and gives a good red shade in the finished paper; acid blue R (color index No. 672) dissolves in the acid bath with a brownishgreen 'color that gives a good blue color effect in the paper; acid blue C F (color index No; 671) dissolves in the acid with a blue color and gives the same effect in the paper after treatment; acidviolet 4, B N S (color index No. 695) dissolves in the acid bath with'a yellow color and dyes the paper purple after passing through thewash bath; acid green double (color index No. 666) dissolves with a yellowish-brown color but. gives a good green coloring elfect in the paper; and similarly naphthylamine black D (color index No. 308) producesa blue-black solution and produces a good black finished paper.

On the other hand, I found some dyes, as, for example, pontamine yellow (color index No. 365) and polar red B concentrated (color index No. 430) are permanently destroyed by the acid and can therefore not be used for the purpose stated.

In general, therefore, it Will be seen that the paper produced by this process affords a wide range of color; that the dyes are incorporated in the amyloid film; that the shade of color can be readily controlled by the amount and character of the dye put into the acid bath, which cannot be so well and conveniently done when the coloring matter is intrdouced into the heaters. Obviously the amount of dye depends upon the nature of the dye itself and the depth of color which it is desired to obtain, and will vary considerably, ranging from, say, a fraction of an ounce to several ounces per pound of acid.

To illustrate the further detail my manner of producing this improved colored parchment paper or vegetable parchment, I give the following examples of the manner in which the process is employed, wherein it will be noted that the process is modified somewhat according to the nature of the dye in its relation to the acid bath:

1. Dye soluble in water and in acid giving colored dye-oath.From one one-hundredth of an ounce to ten ounces of chinoline yellow (color index No. 801), orsome similar dye, depending on the shade desired, is thoroughly dissolved in the parchmentizing acid bath, the above amount being added per pound of acid in the bath. The paper is run through the bath in the usual manner and washed in the usual manner, the resulting parchment being dyed a light, pale, or deep shade of yellow, according to the amount of theg' dye added to the bath.

2. Dye soluble in water and in acid giving colorless dye-bath.-From one one-hundredth to ten ounces of auramine 0 (color index No. 655) or similar dye,,depending on the'shade desiredisdissolved in the parchmentizing bath per pound of acid, and which, in this case, gives a colorless bath. The paper is passed through the bath in the usual manner. On going into the washing bath of water, the color develops as the acid in the paper becomes diluted and is washed out, and the parchment so formed is left a light or deep shade of yellow, according to the amount of dye used in the bath.

3. Bye soluble in water but insoluble in acid.From one one-hundredth to ten ounces of Erie fast scarlet (color index No. 326) or some similar dye, depending on the shade desired,'is ground up with a small amount of sulphuric acid from the parchmentizing bath, until a fine suspension of the dye in the acid is obtained. This'is added to the parchmentizing bath so-that the above amount is contained in one pound of parchmentizing acid. The paper is run through in the usual manner and washed in the giving acid and water solutions which are different in col0r.-The same procedure as described in Examples (1) or (2) is followed with a dye-such as acid violet t B N S (color index No. 695) or some similar dye. Acid violet 4 B N S forms a yellow dye-bath with the sulphuric acid. The paper is put through the usual manner, and upon washing the yellow changes to violet, and the paper is dyed a shade of violet depending on the concentration of dye used in the acid.

5. Dye insoluble in water but soluble or partially soluble in acid.'Ihe dye is dissolved in the acid or a suspension is made in the acid similarly as described in Example (3) in an amount equal to from one one-hundredth to ten ounces per pound of parchmentizing acid. Naphthylamine black I) (color index No; 308) or some similar dye is used and the paper run through in the usual manner. Upon washing out the acid the dye is precipitated by the water and is firmly fixed in the amyloid.

I am thus enabled also -to produce, for the first time, parchmentized paper containing various dyestufis which it has hitherto been impossible to use in the manufacture of such papers, namely, dyes which are not watersoluble. And, by this new method I am not only enabled to produce colored parchmentized papers in a greater variety of colors and shades, with less otherwise un avoidable loss of dyestuffs, and with more satisfactorily constant and controllable effects, owing to the greater latitude in the choice of classes of dyes which may be employed in the manufacture of colored paper parohmentized by the methods described, but I am also enabled thereby to produce colors not hitherto attainable with the hitherto known and applied methods. 4

In the first place, the old method of applying the dyestuff in the heaters required that the coloring matter used be water-soluble. In addition to the disadvantage in the loss of coloring material by such process, this prescribeda limitation in the choice of dyestuffs, necessarily limiting the variety of colors and shades. Furthermore, beyond the required quality of water-solubility, dyestuffs applied in the-boaters must also be basic dyes in order that they would color the fibcr of the paper as it has not beeniconsidered competent to use any mordant in a paper which was to undergo the parchmentizing treatment in the acid bath. Makers of such paper were therefore limited substantially to water-soluble basic dyes for the purpose of dyeing of the paper by the process of coloring in the beat-- ,ers. The process of coloring the paper after its formation and before parchmentizing by impressing or imprinting the dyestulf upon the paper by rollers carrying such colors is also limited to water-soluble dyes.

If any kind of a uniform color was to be expected such colors had to be insoluble in acid because otherwise the color impressed upon the paper from the rollers would again be dissolved off by the acid bath.

By being able to apply more varieties and classes of dyes which I have found can be used directly in the acid parchmentizing bath, I develop not only a superior product, but am enabled to make new grades of such paper incorporating dyes of a character which have never been used for the purpose. All of the limited numbers of dyes hitherto employed can also be used in my process, while with all the additional dyestuffs which I am enabled to use I can produce colored parchmentized papers of colors and shades heretofore not known in the art. Especially I am enabled to produce a black parchmentized paper of deep shade which it has not been possible to do satisfactorily by the old processes. It will also be evident, from the foregoing explanations and examples, that appropriate mixtures and combinations of .colors may be made to produce numerous tints and shades in parchmentized paper hitherto entirely unknown in this art. a

One of the advantages of my method of coloring these papers is that it permits closely coordinated control. After experiment has once determined just what mixtures and proportions are to be employed in order to produce any specialized color, shade, or tint, it is a relatively simple matter to so control the acid bath that it will be at all times of sub-.

stantially the same composition, and the finished paper can be produced always in close approximation of the selected standard of color or tint. I

Sulphuric or other acids or materials have been used in parchmentizing baths, but the former is preferably employed because of its gerater availability and relative cheapness.

- I have therefore described my process of instantially the same manner as herein set forth.

It is also obvious from the description of the process herein set forth that its is possible to make considerable variation in quantity and qualities of the dyes used according to the colors, shades, or general effects which it is desired to produce, Without departing from the nature and scope of my invention, and I wish to have it understood that the examples given in this specification have been embodied for the purpose of illustration, and not by Way of limitation.

What I claim as new. and for which I pray the issuance of Letters, Patent, is:

1. In the art of manufacturing colored or tinted parchmentized paper, the'process of passing the formed paper through an acid bath in which is dissolved dyestufl, and sub sequently passing the paper so treated througha water bath to dissolve or wash out the acid still present.

2. In the art of manufacturing parchmentized paper of the character described, a step in the process, comprising the treatment of the paper with an acid bath in which dyestufi' is dissolved.

3. In the art of manufacturing parchmentized paper of the character described, a step 1n the process comprising the treatment of the paper With a parchmentizing bath in which dyestulf is dissolved.

4. In the art of manufacturing parchmentized paper of the character described, a step in the process, comprising the treatment of the formed paper by immersing the same in a parchmentizing bath in which organic dyestuff is dissolved.

5. A parchmentized paper incorporating dyestuffs soluble in acid but not soluble in Water.

6. Parohmentized paper incorporating ggpgithylamine black D (color index No,

7. In the process of parchmentizing paper, the addition of dyestuffs to an acid parchmentizing bath.

8. In the process of manufacturing colored or tinted parchmentized paper Whichembraces a step consisting in treating such paper in an acid bath, the addition of the dyestuff to said acid bath.

9. In the process of manufacturing colored or tinted parchmentized paper which embraces a treatment of such paper in an acid parchmentizing bath, a step consisting of the addition to said bath of dyestulf which Will not be destroyed by the acid of the bath.

10. In the art of manufacturing colored or tinted parchmentized paper, the process of passing the formed paper through an ac1d bath in which is dissolved coal-tar dye-stuff, and subsequently passing the paper so treated through a water bath to dissolve or Wash out the acid still present.

11. Parchmentized paper which has incorporated therein a black organic acid-soluble ROBERT IRVING COWEN. 

